1. Field of the Invention
This invention generally relates to a shift operating device for operating a bicycle component. More specifically, the present invention relates to a shift operating device that has a support structure that allows its shift control unit to be easily replaced.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle, especially the shift operating devices for performing shifting and braking operations.
Typically, bicycle shifters mechanically operate derailleurs via cables, while bicycle brake levers mechanically operate brake devices via cables. In either case, an operating force is typically applied by one of the rider's fingers to operate a control lever, which in turn transmitted the operating force to the drive component of a bicycle shifting mechanism by a cable that was fixed at one end to the control lever. Currently, many different types of control devices exist for performing shifting and braking operations.
Sometimes the bicycle shifter and the bicycle brake lever are combined as a single integrated unit, while other times they are separate individual units. In the case of road bikes with drop type handlebars, the bicycle shifter and the bicycle brake lever are often combined as a single integrated control device. In some cases, a braking function and a shifting function is performed by a single dual function lever, One example of this type of control device is disclosed in U.S. Pat. No. 5,400,675 to Nagano (assigned to Shimano, Inc). More typically, one or two shift levers are provided in addition to the brake lever. One example of this type of control device is disclosed in U.S. Pat. No. 5,257,683 to Romano (assigned to Campagnolo).